diff --git a/ansible/roles/sway/files/waybar_config.json b/ansible/roles/sway/files/waybar_config.json
index 4d13bc9..1b3d667 100644
--- a/ansible/roles/sway/files/waybar_config.json
+++ b/ansible/roles/sway/files/waybar_config.json
@@ -20,7 +20,7 @@
     "spacing": 10
   },
   "custom/clock": {
-    "exec": "waybar_custom_clock",
+    "exec": "waybar_custom_clock 'America/New_York'",
     "return-type": "json",
     "restart-interval": 30
   }
diff --git a/ansible/roles/sway/files/waybar_custom_clock.py b/ansible/roles/sway/files/waybar_custom_clock.py
index 9cef0b2..6a2fe35 100644
--- a/ansible/roles/sway/files/waybar_custom_clock.py
+++ b/ansible/roles/sway/files/waybar_custom_clock.py
@@ -1,13 +1,17 @@
 #!/usr/bin/env python
 #
 # Custom waybar module for clocks. Implemented because the official clock module was downloading timezone definitions on every boot.
+import datetime
 import json
 import sys
 import time
 from dataclasses import dataclass
+from functools import lru_cache
 from typing import Final, List, Optional
+from zoneinfo import ZoneInfo
 
 INTERVAL: Final[int] = 10
+LOCAL_TIMEZONE = datetime.datetime.now(datetime.timezone.utc).astimezone().tzinfo
 
 
 @dataclass
@@ -35,17 +39,56 @@ class Update:
         )
 
 
+@lru_cache(maxsize=1)
+def make_calendar(today: datetime.date, tz: datetime.tzinfo):
+    width: Final[int] = 20
+    start_of_month = today.replace(day=1)
+    month_header = today.strftime("%B %Y")
+    padding = width - len(month_header)
+    right_padding = " " * (padding // 2)
+    left_padding = right_padding + (" " if padding % 2 == 1 else "")
+    header = f"{left_padding}{month_header}{right_padding}"
+    days_of_week = "Su Mo Tu We Th Fr Sa"
+
+    # Make the grid
+    first_day_padding = " " * (
+        0 if start_of_month.weekday() == 6 else (3 * (1 + start_of_month.weekday())) - 1
+    )
+    output = f"{header}\n{days_of_week}\n{first_day_padding}"
+
+    print_day = start_of_month
+    while print_day.month == today.month:
+        if print_day.weekday() == 6:
+            output += "\n"
+        else:
+            output += " "
+        output += f"{print_day.day: >2}"
+        print_day += datetime.timedelta(days=1)
+    return output
+
+
 def main():
+    tz: Optional[datetime.tzinfo] = (
+        ZoneInfo(sys.argv[1]) if len(sys.argv) >= 2 else LOCAL_TIMEZONE
+    )
+    if tz is None:
+        raise Exception("Failed to detect timezone.")
+
     next_update = time.time()
     while True:
         time_before_next_update = next_update - time.time()
         if time_before_next_update > 0:
             time.sleep(time_before_next_update)
         next_update = time.time() + INTERVAL
-        argv = json.dumps(sys.argv)
+
+        now = datetime.datetime.now(tz=tz)
+        text = now.strftime("%Y-%m-%d %H:%M")
+        tooltip = make_calendar(now.date(), tz)
+
         out = Update(
-            text="foo", alt=argv, tooltip=argv, css_class=["foo"], percentage="100"
+            text=text, alt="foo", tooltip=tooltip, css_class=["foo"], percentage="100"
         )
+
         print(out.dump(), flush=True)